title: Determination of cathinones and related ephedrines in forensic whole-blood samples by liquid-chromatography-electrospray tandem mass spectrometry.
abstract: A liquid-chromatography-tandem-mass-spectrometry method using pneumatically assisted electrospray ionisation (LC-ESI-MS/MS) was developed for the simultaneous determination of cathinone, methcathinone, ethcathinone, amfepramone, mephedrone, flephedrone, methedrone, methylone, butylone, cathine, norephedrine, ephedrine, pseudoephedrine, methylephedrine and methylpseudoephedrine in human live and post-mortem whole blood. The blood proteins were precipitated by the addition of methanol, and the extract was purified by ultrafiltration. The separation of diastereomeric ephedrines was achieved on an ethyl-linked phenyl column. Matrix-matched calibrants combined with the isotope dilution of selected substances were used for quantitative analysis. The relative intra-laboratory reproducibility standard deviations were generally better than 7% at concentrations of 20 μg/L, and the mean true recoveries were 87-106% in the concentration range of 10-250 μg/L. The detection limits were in the range of 0.5-3 μg/L. The cathinones were unstable in whole blood and sample extracts under neutral conditions, but the stability could be improved by the acidification of the sample matrix.
authors.affiliation: Section for Toxicology and Drug Analysis, Department of Forensic Medicine, Aarhus University, Aarhus N, Denmark. lks@forensic.au.dk
authors.forename: Lambert K
authors.initials: LK
authors.lastname: Sørensen
mesh_terms: D000470:Alkaloids / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D004809:Ephedrine / Q000031:analogs & derivatives* / Q000097:blood*; D006801:Humans; D000432:Methanol / Q000737:chemistry; D025341:Principal Component Analysis; D011427:Propiophenones / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000470:Alkaloids; D011427:Propiophenones; C023665:cathinone; D004809:Ephedrine; D000432:Methanol